基于扭摆腔与被动调Q技术的单纵模激光产生技术研究

发布时间：2018-05-26 09:32

本文选题：单纵模 + 固体激光器　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：自从激光器诞生以来,国防建设、工业生产、信息通讯等对激光器的需求不断上升。特别是具有高能量、高重复频率、高稳定性和光束质量的固体激光器,在激光光谱学、光参量振荡器泵浦、激光诱导等离子体、激光雷达惯性约束核聚变有着不可取代的作用。而这些激光器都需要一个稳定、高效的种子源,即单独的一个单纵模激光器模块。本文首先介绍了单纵模固体激光器的国内外研究进展,分析了目前单纵模固体激光器的整体发展情况和趋势,以及在应用上的不足,提出了本文的主要研究内容。然后由琼斯矩阵推导并验证了扭摆结构对空间烧孔效应的解决。从整体上对腔内反转粒子数的分布和调制深度进行研究,得到了不考虑输出镜透过率情况下的最优调Q晶体透过率。结合加入衍射损耗的调Q的速率方程的计算仿真,得到了与国外理论研究符合的调Q输出参数的变化趋势。根据腔内的振荡频谱的特性,验证方法的可行性。其次,设计了不同的振荡器结构,验证不同腔型对扭摆腔结构有不同的匹配程度。通过改变调Q晶体透过率、扭摆结构的波片角度、腔长和重复频率,得到了和理论相符合的结果。最后,该谐振腔得到了单脉冲能量9.7mJ,脉冲宽度10.07ns,重复频率在1~5Hz可调的的激光脉冲,M2因子在x和y轴分别为1.23和1.47,单纵模几率大于98%。对该脉冲利用折返池SBS结构成功的将谐振腔输出光束压缩至500ps,能量反射率为22.2%。结合两种技术能够为工业生产和科学实验提供峰值功率更高的单纵模激光器。
[Abstract]:Since the birth of lasers, the demand for lasers has been increasing in national defense construction, industrial production, information communication and so on. In particular, solid-state lasers with high energy, high repetition rate, high stability and beam quality play an irreplaceable role in laser spectroscopy, optical parametric oscillator pumping, laser-induced plasma and inertial confinement fusion of lidar. These lasers require a stable and efficient seed source, that is, a single longitudinal mode laser module. This paper first introduces the research progress of single longitudinal mode solid-state lasers at home and abroad, analyzes the overall development and trend of single-longitudinal-mode solid-state lasers at present, as well as their shortcomings in application, and puts forward the main research contents of this paper. Then the solution of space hole burning effect of torsion pendulum structure is deduced and verified by Jones matrix. The distribution and modulation depth of the number of inversion particles in the cavity are studied as a whole, and the optimal transmittance of Q-switched crystal is obtained without considering the transmittance of the output mirror. Combined with the calculation and simulation of the rate equation of Q-switched with the addition of diffraction loss, the variation trend of the Q-switched output parameters in accordance with the theoretical research abroad is obtained. The feasibility of the method is verified according to the characteristics of the intracavity oscillation spectrum. Secondly, different oscillator structures are designed to verify that different cavity types have different matching degree for torsion pendulum cavity structure. By changing the transmittance of Q-switched crystal, the wave plate angle, cavity length and repetition frequency of the torsion pendulum structure, the theoretical results are obtained. Finally, the single pulse energy is 9.7 MJ, the pulse width is 10.07 ns, the M _ 2 factor of laser pulse with tunable repetition rate at 1~5Hz is 1.23 and 1.47 in x and y axis, and the probability of single longitudinal mode is greater than 98. The output beam of the resonator is compressed to 500psusing the SBS structure of the reentrant cell, and the energy reflectivity is 22.22. The combination of two techniques can provide a single longitudinal mode laser with higher peak power for industrial production and scientific experiments.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248

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